I saw this and was interested. Most of my diving is done 40-65 miles from shore in the GOM off my own boat, so this type of device would obviously be nice to have in that type of situation. I always have varying degrees of topside help, some keep a watchful eye some don't, just the nature of the game. There are a few things I can think of offhand that have happened or could that cause a diver to surface off the site in heavy current and high waves (ie: bad skills, work boats moving in and not keeping a safe distance from the flags, squalls move in quickly, etc). Also, stuff happens out there and boats sink, anchors slip. What a nitemare it would be to come up and no boat.
Anyhow, when I first saw this device I was excited because I thought it had a PLB on it too. That would be the cats arse.
I purchased an ACR plb and OMS was making a canister that it would fit in. Right after I got the plb the OMS canister was discontinued and I can't find anything to put it in. Looking at possibly rigging a diverite light canister now. McMurdo makes the Fastfind that will fit into a canister that they make but I'm too late for that now unless I sell the ACR and buy the other, there were reasons I leaned toward the ACR though.
The radio could have a lot of benefit in the oil patch since there are many platforms and workboats monitoring VHF.
Sorry to get off topic a little but in summary:
Somebody make something like this with integrated plb and you will have at least one sale.
